In general, printed circuit boards, in which connection of components using respective wires in related arts is excluded and electrical paths of circuits are formed by printing conductive patterns on the boards, are indispensably required for integrating circuits and have been widely used recently in all electronic and electrical circuits.
When elements are mounted on a printed circuit board and a power is supplied, heat is inevitably generated due to resistive components disturbing the current flow between conductive patterns and elements on the printed circuit board. When heat is generated, a case occurs in which elements, such as a microprocessor, an FET, and a regulator, are sensitive to heat and malfunction due to the heat. In particular, due to active technical development of surface mount devices, technology has been developed into a type in which a lot of elements are mounted in one printed circuit board, and a phenomenon in which heat generated in any one component affects other components may also occur.
As such, in order to address the problem in that heat is generated on a printed circuit board, various techniques have been actively studied also in related arts to dissipate heat, and a separate configuration such as a heat sink or cooler has been used to solve the heat generation problem.
In addition, when a charging/discharging FET is mounted on a printed circuit board, in order to solve the heat generation problem in related arts, a separate heat dissipating plate is installed close to the FET to prevent the FET to be overheated. In this case, due to a limit in the sizes of the charging/discharging FET and the heat dissipating plate, it is difficult to manufacture a battery pack in a small size.
Accordingly, in order to solve the heat generation problem, a technique, in which heat is less generated when current flows, the generated heat is dissipated to the outside, and a battery pack may be manufactured in a small size, is required.